THE RETINA. 



503 



cent researches seem to have determined that this membrane, 

 instead of being, as was formerly considered, an independent 

 covering, is intimately associated, both in structure and func- 



FIG. 182. 



FIG. 182a. 



FIG. 182. Vertical section of retina of human eye. 1, bacillar layer ; 2, outer layer 

 granular; 3, intermediate fibrous layer; 4, inner granular layer; 5, finely granular 

 gray layer; 6, layer of nerve-cells ; 7, layer of fibre of optic nerve; 8, limitary mem- 

 brane. 



FIG. 18'2a. Elements of human retina. 1, large fibre of optic nerve; 2, very fine 

 fibre of the same; 3, rod with a granule,/, attached; 4, a similar rod with a fine fibrous 

 prolongation, connecting it with the granule ; 5, portions of rods altered by the action 

 of water; 6, 7, two cones, b b, with their nuclei, c c, their bacillar portions, d d, and 

 their fine fibrous prolongations, ee; 8, radiating fibre, ee, with granule of outer layer, 

 y, and subdividing in the bacillar layer, as well as in the optic layer, h; 9, connec- 

 tion of rods, a, with granules of inner layer,/, granule of outer layer, g, and expan- 

 sion of the fibre proceeding from the latter in the optic layer at h; 10, similar con- 

 nection of cone, b, c, with granule, g, and with nerve-cell, I, which has another 

 librous prolongation, ni. 



tion, with the sensitive part of the retina; for the conical and 

 staff-shaped bodies, of which it is composed, appear to be con- 



